Department of Orthodontics, Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
Am J Orthod Dentofacial Orthop. 2010 Mar;137(3):375-8. doi: 10.1016/j.ajodo.2008.03.030.
The purpose of this study was to evaluate the shear bond strength of orthodontic brackets and the effect of an enamel bonding agent (EBA) on enamel surface after debonding.
Seventy-five extracted maxillary premolars were collected and randomly divided into 3 groups of 25. The enamel cracks were surveyed with a stereomicroscope. In the first group, 1 layer of EBA was applied before the adhesive resin. In the second group, 2 layers of EBA were used; in the third group, no EBA was used. Bonding was followed by incubation for 48 hours at 37 degrees C and thermocycling for 1000 cycles. Debonding was performed with a shear force. The surfaces of the teeth were evaluated, and the length, depth, direction of cracks, and adhesive remnants on the enamel surface were recorded. Data were analyzed by using analysis of variance and paired samples t tests.
There were no significant differences between the shear bond strengths (P = 0.341) of the 3 groups, or in the direction, length, and depth of the cracks before and after debonding (P > 0.05). There was a significant increase in the number of cracks after debonding in the 3 groups (P < 0.05). The evaluation of adhesive remaining on the surface of the teeth indicated that most bond failures occurred at the resin-bracket interface.
The use of EBA does not enhance bond strength or provide greater protection to the enamel surface during debonding.
本研究的目的是评估正畸托槽的抗剪粘接强度以及脱落后釉质表面的牙釉质粘接剂（EBA）的效果。
收集 75 颗上颌前磨牙，随机分为 3 组，每组 25 颗。使用立体显微镜观察釉质裂纹。第一组在粘接树脂前使用 1 层 EBA，第二组使用 2 层 EBA，第三组不使用 EBA。粘接后在 37°C 下孵育 48 小时，然后进行 1000 次热循环。用剪切力进行脱粘。评估牙齿表面，记录釉质表面上的裂纹长度、深度、方向和残留的粘接剂。使用方差分析和配对样本 t 检验对数据进行分析。
3 组间的抗剪粘接强度无显著差异（P = 0.341），脱粘前后裂纹的方向、长度和深度也无显著差异（P > 0.05）。3 组脱粘后裂纹数量均显著增加（P < 0.05）。对牙齿表面残留粘接剂的评估表明，大多数粘接失败发生在树脂-托槽界面。
使用 EBA 不能增强粘接强度或在脱粘过程中为釉质表面提供更大的保护。
